Exploring the Deep Pacific

EXPLORING THE DEEP PACIFIC By HELEN RAITT Copyright © 1956 By W. W. Norton & Company, Inc. FIRST EDITION Library of Congress Catalog Card No. 56-10089 PRINTED IN THE UNITED STATES OF AMERICA FOR THE PUBLISHERS BY THE VAIL-BALLOU PRESS CONTENTS Introduction by Roger R. Revelle ix 1. South Sea Meeting 3 2. My Tongan Family 17 3. Polynesian Christmas 28 4. It’s a Man’s World 35 5. The Disappearing Island 45 6. Night Exploration 56 7. We Cross the Deep 63 8. The Big Winch 73 9. New Year’s Day on the Tonga Trench 81 10. Undersea Everest 94 11. Nofoa Tonga 110 12. Pago Pago 125 13. The Long Shot 132 14. Palmerston—A Family Affair 147 15. Point Mike 158 16. Tahiti 168 17. Storm 180 18. An Atoll Rich in Mystery 184 19. Nukuhiva, Land of Typee 206 20. Coral Reefs and Atolls 217 21. Sight! Surface! 227 22. Helen Seamount 236 23. Alone on This Desert of Ocean 238 24. Extruder Extraordinary 241 25. Operation “Concussion” 252 26. The Beautiful Has Vanished 266 Bibliography 270 v ILLUSTRATIONS Photographs between pages 128 and 129 The Spencer F. Baird and the Horizon of Expedition Capricorn Lowering the corer barrel Putting over the temperature probe The Baird’s fantail The 40,000-foot cable aboard the Baird Gustaf Arrhenius and Roger Revelle examine a gravity core The hydrophones are streamed Russell Raitt examines seismic records The echo sounder records the ocean bottom The author typing up the log Walter Munk examines a coral formation Takaroan pearl divers with Capricorn’s Willard Bascom Marquesans perform dance of the loving pigs Scientists of the Baird MAPS and DRAWINGS Track of Expedition Capricorn endpapers Profile of Spencer F. Baird, showing main features Page39 Profile of Kao Island 58 Tonga Trench is deeper than Everest is high 64 Map of the Tonga Trench region 65 Bottom layers in the Tonga Trench area 87 Guide to the interior of the Earth 108 How the seismic waves were transmitted 139 Bathymetric and magnetic contours, Palmerston Atoll 153 Comparative profiles of volcanic islands, seamount, and coral atoll 202 Three stages in the formation of an atoll 204 A typical core record sheet 245 vi INTRODUCTION ROGER REVELLE Scripps Institution of Oceanography, University of California, La Jolla, California. Have you ever asked yourself: “Why is there an ocean?” This question probably would not occur to a fish. Immersed all his life in his watery medium, he would think the universe must be made mostly of water, and that such a state of affairs is natural and proper. Nor, unless we give special thought to the matter, is the question likely to be asked by us human beings. The ocean is so incomprehensibly big, so noisily uncommunicative, so alien to our human affairs, that we are likely to take it for granted as simply one of the background facts of life. But to a man from Mars, on Earth for his first visit, our ocean would be a major mystery. His own planet is dust-dry; there is scarcely enough water on its surface to make a little cap of hoar frost around the poles in winter. The Venusians, Saturnians and Jovians would be equally puzzled, for Earth is the only planet with seas and dry land. So far as we know, there is no water at all on Venus. There is plenty on Saturn and Jupiter, but it is frozen in great shells of ice and snow that cover their entire surfaces. Only on Earth are the waters gathered together in a world-girdling vii viii ocean, surrounding the great islands that we call continents. The pattern of sea and land on Earth makes our own lives possible, and it provides diverse environments for the wonderful variety of living things that share our planetary home. The scientists who study Earth, and try to decipher her long history, are convinced that this pattern is no accident. In part it may have originated when our globe was being formed, four or five billion years ago. But to begin with, the oceans were probably small; the mighty flood of waters we see today may have grown almost drop by drop, throughout the lifetime of our planet, from water seeping out of the interior. We oceanographers have never been able to make up our minds as to what actually happened, because in fact we know so very little about the ocean. If you pick up in your hands a terrestrial globe and hold it so that Tahiti and the surrounding islands are directly in front of your nose, you will see almost an entire hemisphere of blue, with only bits of North America and Australia cutting into the edges. This is the Pacific. The German geographers used to call it “der Grosse oder Stille Ozean”—the Great or Quiet Ocean—in blissful ignorance of its roaring gales and terrible hurricanes. The very existence of the Pacific has been known to white men for only a few hundred years. Less than 200 years ago, say at the time of the Boston tea party, most of the islands that dot its surface had never been seen by a European or an American. Today all the islands are on charts, though often the chart makers are not quite sure about their size or shape or exact location. But the land beneath the waters is still largely unknown. There are many areas of tens of thousands of square miles without a single sounding. One can hardly go out over the deep Pacific in modern oceanographic ships without discovering ix several previously unknown submerged mountain peaks, and sometimes even a mountain range beneath the sea. This ignorance is not for want of trying. Beginning with the great British Challenger Expedition in 1872–1876 there have been many oceanographic and hydrographic expeditions into the Pacific. But the scale of effort was inevitably small in comparison with the giant size of that ocean. Moreover, until the last few years, the methods for penetrating beneath the sea surface were inadequate to give more than a vague, and in many respects a quite erroneous, picture. The only way to find the bottom depth was to lower a long wire into the water with a weight at the end, and to measure the length of wire paid out when the weight touched the bottom. It was as if surveyors were trying to make a map of the United States by flying in a blimp above a cloud layer and lowering a wire from the blimp once or twice a day! One day during World War II, I received a telephone call from a young lady in our Navy’s Bureau of Ordnance. “What is the bottom of the ocean like?” she asked. “I need to know for a classified development project.” As an oceanographer masquerading temporarily as a Naval officer, I was shocked. How could anyone ask such a simple question about such a complicated subject? I told her that if she would come over to my office I would give her a lecture of several hours’ duration. But she said she was in a hurry and hung up the phone after I told her that in some places the deep sea floor is rough, hilly, and rocky, while elsewhere it is flat and muddy. Over the succeeding years I have occasionally thought about this young lady. I have slowly come to realize that in fact she extracted from me in that one sentence all I knew at the time about the floor of the deep sea. It is only because of the oceanographic research that began x on a large scale during the war, and has been continued more intensively since, that we are beginning to get a real picture of the broad features of the deep-sea floor, and some idea of the curious and characteristic ways in which it differs from the familiar surface of the land. The development of electronic art has made possible new methods of oceanic exploration. For example, with the aid of a marvelous gadget called the recording echo sounder, we are able to send a short, sharp sound straight down toward the sea bottom (somewhat like clapping our hands through a megaphone) and to measure the time required for the echo to return from the bottom to the ship. Such depth measurements can be made quickly and continuously, and recorded automatically on a chart, so that we can make a profile or cross section of the shape of the sea floor along the ship’s track. By putting the cross sections from many cruises together we shall eventually have a map of the land under the sea almost as accurate and detailed as our present-day maps of Mexico and South America. The Scripps Institution’s Capricorn Expedition, which Mrs. Raitt has described in this book, was one of a series of exploring expeditions into the deep Pacific sent out by many countries since 1946. Other expeditions, some of them much longer and more ambitious in scope, have been carried out by the Swedes, the Danes, the British, and the Russians. All these cruises had essentially the same purpose: they were voyages of discovery in which new instruments for oceanographic exploration were pitted against the vast unknown of the Pacific Ocean. Our expedition differed from the others chiefly in the variety of instruments used and in the greater diversity of interests of the scientists on board. Some of the members of the expedition were interested in the electric currents in the atmosphere; others wanted to xi measure the speed and variability of the water motions in the sea, or to collect the tiny floating plants and animals called plankton.

Load more